The invention relates to an agricultural round baler for forming round bales of harvested crop, the round baler comprising a press chamber that is provided with a rearward outlet for ejecting the completed round bale and with pressing devices that cause the harvested crop to rotate; a harvested crop pickup device; a cutting and/or conveying device; a storage chamber that adjoins the cutting and/or conveying device and reaches to an inlet area of the press chamber. The storage chamber, in storage phases of the pressing operation, receives and stores harvested crop. A control or governing device for controlling devices for interrupting or releasing crop transfer from the storage chamber to the press chamber is provided. A device for tying the completed round bale with tying material in the pressing chamber is provided.
The invention moreover concerns a method for controlling the flow of harvested crop in such an agricultural round baler.
Round balers are often employed for processing stalk crop. They are characterized by a relatively simple configuration and minimal drive output in comparison to large square balers. A disadvantage is however that upon processing with a round baler there is the problem that during the processing steps of tying and ejecting the completed bale, it is not possible to continue to supply harvested crop material. The method is carried out in a stepwise fashion. This means that in a first step the harvested crop, as the baler travels across the field, is picked up, shaped to a round bale, and compressed. In a second step, by stopping the tractor, the pickup of harvested crop is interrupted, the bale is compressed to the final state, and then is tied with yarn or a net and ejected from the press chamber. The tying process and the ejection require a significant amount of time that may even reach the duration of the preceding bale forming step. For a long time, there have been attempts to avoid these undesirable interruptions in operation in order to thus in crease the baler performance significantly.
In order to eliminate the disadvantages of the stepwise method, a baler must be developed which is able to continuously pick up harvested crop. In order to achieve a continuous material supply, the harvested crop must be stored intermediately during the tying and ejecting interval. At the beginning of a new working cycle, within the shortest possible time, the intermediately stored material must be supplied to the press chamber while simultaneously newly picked-up material continues to flow. In the various proposals for solving this problem, two basic systems have been developed.
In the “multi-chamber” basic principle, as disclosed inter alia in the publication DE 27 04 982 A1 and DE 10 2005 020 777 A1, the main press chamber has upstream thereof a smaller pre-compression chamber in which during the tying process the harvested crop that is continuously being picked up is wound and compressed to a pre-bale. After the main press chamber has been emptied, this pre-bale is to be transferred from the antechamber into the main chamber, while simultaneously harvested crop continues to be supplied, in order to be completed in the main chamber. In particular the transfer of the pre-bale into the main chamber during which the pre-bale should not lose its shape and compression state is in practice very problematic and requires an extremely high constructive expenditure.
Continuously operating round balers operating based on the afore described basic principle of at least two pressing and winding chambers therefore have not yet surpassed the experimental stage, most likely because of these problems.
In the various proposals for continuous round balers that operate according to the “single-chamber” basic principle, the harvested crop that is picked up upon further travel during bale formation is supplied to a storage chamber that is positioned upstream of the press chamber. A problem in connection with such continuously operating bale presses, as disclosed inter alia in EP 0 350 514 A1 and DE 199 32 336 A1, is however the removal of the harvested crop that has been collected in the storage chamber. When removal from the storage chamber takes place too slowly while at the same time additional harvested crop is supplied as a result of continued travel of the baler, the performance limits of the baler are reached quickly and an uninterrupted continuous operation without reduction of the travel speed is not possible. A further disadvantage resides in that the crops that has been pre-compressed within the storage chamber to a limited extent after transfer into the empty press chamber will expand again and therefore desired bale densities will no be achieved.
Continuously operating round balers according to the single-chamber basic principle have reached marketability but, in particular because of the unsatisfactory performance, they have not found acceptance in practice.
Based on this, it is an object of the present invention to provide an improved continuously operating round baler that eliminate the disadvantages of the prior art and further develops the prior art devices in an advantageous manner.